Projections of Solids Introduction An object having three dimensions, i.e., length, breadth and height is called as solid. In orthographic projection, minimums of two views are necessary to represent a solid. Front view is used to represent length and height and the top view is used to represent length and breadth. Sometimes the above two views are not sufficient to represent the details. So a third view called as side view either from left or from right is necessary.

Objectives At the end of this session, you will be able to • Classify the different types of solids • Draw the projections of solids in various positions in the given quadrant

Classification of Solids Solids are classified into two groups. They are • Polyhedra • Solids of Revolution

Polyhedra A solid, which is bounded by plane surfaces or faces, is called a polyhedron. Polyhedra are classified into three sub groups; these are 1. Regular Polyhedra 2. Prisms 3. Pyramids

Regular Polyhedra Polyhedra are regular if all their plane surfaces are regular polygons of the same shape and size. The regular plane surfaces are called "Faces" and the lines connecting adjacent faces are called "edges".